When Hapsburg Empress Elizabeth Was stabbed to death, the bodice of her dress was so tight it served as a tourniquet. The lady never bled.

Her dress, as well as lavishly decorated court uniforms, ceremonial robes, livery, saddles, swords and the celebrated Winterhalter portrait of Elizabeth, are part of the new costume collection, Fashions of the Hapsburg Era: Austria-Hungary, which opens today at the Metropolitan Museum of Art in New York. The show will continue through next summer.

Through the dazzling court dress, now on display, one discovers the fairy tale court of the Hapsburgs, the longest continous reign of a royal family in Europe.

The oldest of the more than 150 costumes is a deep purple patterened velvet coat worn by a Hungarian nobleman in the 17th century. The exhibit spans through the products of the early 20th century workshops of the Wiener Werkstatte, where artists broke with tradition and incorporated new technology and new esthetic values more in keeping with the changing lifestyle.

The strength of the show, however, is more in the 19th century, when Vienna was a cultural and social center of Europe. Tailoring and textile expertise became Vienna specialties in this period, preparing the way for Franz Josef, who in 1849 demanded that others follow his regimen of always wearing uniforms.

But what separetes this show from many that preceded is the impact of the men's clothes. While only about one third of the costumes are for men, they are far more grand, more interesting and more decorative than the women's.

If the show has all the schmaltz of a Nelson Eddy-Jeannette MacDonald operetta, it lacks the punch of some of the museum's previous shows. The show will undoubtedly be compared often with the Russian show, where the costumes were more bold and overscale. It is hard to top Peter the Great's boots or Catherine the Great's 19-inch waist.

Even Elizabeth, with a 20-inch waist at age 50 is no real match for Catherine the Great. A late bloomer as far as fashion was concerned, Empress Elizabeth was pretty fascinating. She had herself sewn into a calfskin body suit each time she went horseback riding . . . the usual protective petticoats would surely make her look too fat. The garment was so impossibly snug that once, when she slid off her horse, she couldn't get up. And the horses she chose to ride were, naturally, huge so that when she was topside she would look especially tall and thin. After the death of her sons, Elizabeth began wearing a mourning mask, which is also on display. It is thought to be a disguise she adapted to make herself more interesting and to hide her aging face.

Those lavishly decorated uniforms worn by both the Austrians and Hungarians at the imperial court, and even the household livery costumes, diminish the impact of the pretty, very feminine dresses worn by the court ladies at the time. The role of women in the court was a minor one that was solely decorative. They occupied themselves mostly by planning their wardrobes and dressing for parties. "They seemed as delicate as pale flower petals and appeared in sharp contrast to the strong vibrancy of their uniformed 'protectors.'" says Stella Blum, the museum's curator of costume.

Blum says there is a need for such a remote, fanciful kind of show at this time. "Our life today is really so difficult," says Blum, that the elegance, the beauty, the dream world of these costumes may be just what people need to see right now.

She compares it to the post-Depression period "when fantasy of movies gave one a chance to think of other things where life does not seem to be so difficult, so hard."

The promise of such a fantasy display no doubt stirred a challenge in the guests attending the gala benefit opening last week.

"It was probably one of the most beautifully gowned group of people I've seen in many years," said designer Donald Brooks.

Unlike the show, which clearly provokes a greater spirit of dress and decoration in the men than the women, the men at the benefit never quite rose to the occasion. "Strictly straight black tie," said jewelry designer Kenneth Jay Lane, who says he wore an 18th-century embroidered black vest under his tux for the occasion. "But no one noticed," he said.

But the glitz and shimmer of the gold- and silver-decorated men's costumes in the show were not missed by the largely fashion-related crowd.

Rank, family and etiquette in the strictly structured, status-conscious period is revealed through the specific type of decoration on the uniforms. Gold trim versus gold embroidery, and even the detail of whether or not the trim was scalloped indicated a man's social and military rank, according to Helga Kessler, Lewisohn Fellow who did much of the research on the exhibition. "You could even tell the position of a servant in the household by the number of rows of curls on his wig," Kessler said.

And by the measure of decoration on the garments one could distinguish between the Austrians and their political and ethnic ties to the West from the Hungarians -- besieged by the Huns in the 9th century, occupied by the Moguls in 1241 and ruled by the Turks from 1541 to 1683. Their costumes show their distinct tilt to Oriental styles.

This is the eighth annual exhibit overseen by Diana Vreeland, special consultant to the Costume Institute, whose handiwork is most apparent in the use of color and sense of fantasy in the models and hairdos.

The exhibit originated with Vreeland's interest in taking a close look at the costumes worn at the Congress or Vienna. Then, over a year ago, Blum and Kessler took off for Vienna to see if such an exhibit might be possible.

To their surprise they found a vast range of costumes in major institutions in Budapest and Vienna in perfect condition . . . some never before exhibited. While some of the women's things have been changed to accommodate style changes in each period, the mens clothes had not. Coats apparently remained in possession of the court and the men took their pants with them when the empire collapsed. "Which is why so many uniforms are shown without pants," Kessler said, laughing.

Blum expected to find more splendid women's dresses. "But Maria Theresa was a good Catholic and gave most of her dresses to the church. Sadly, nothing of hers survives," Blum said.

Blum was impressed by the tailoring, the embroideries, the quality of workmanship she found. "The tragedy of human nature is that when there is a large division between the rich and the poor, there is money to be paid for these great works of art and artifacts, great tailoring and exquisite embroideries. And there is desperation on the poverty level to work that hard to provide the labor for these needs."

If the men's clothes were the more splendid in this period, they were also the most difficult to mount on models. "It was hard to get the same spit and polish," Blum said. She figures men must have worn corsets to keep their figures and postures. And the male mannequins at the Met "had too much beef on their backs." Using padding to make them look erect, Blum concludes that they probably looked even more elegant than they could make them.

Blum didn't have to guess at the posture or stance of the men. "There is body language from the clothes," she insists. "The heat of the body molds the clothes into the shape of the man. The clothes tell us specifically the way men looked then."

Diana Vreeland doesn't think men will want to look like that again. "Men's clothes are getting more and more conventional. The ties are getting narrower, the lapels narrower. Why don't they get cracking? Why won't they at least get to a good shirtmaker," she demanded. "No, I fear this will mean little to the way men dress."

But some things may well rub off on the women. There is a red wool pleated page's coat with black velvet collar and cuffs that will no doubt show up as a woman's coat. "But the tailors simply don't exist anymore to make the kind of coats and jackets that this exhibit could inspire," says Blum.

She does believe, though, that as men stand in front of some of the uniforms they are bound to stand up a little straighter. "But as soon as they leave the museum, they are bound to slouch again," she says.